Device for tensioning bundling straps



Aug. 7, 1962 M. c. LOGAN DEVICE FOR TENSIONING BUNDLING STRAPS 2 Sheets-Sheet 1 Filed Aug. 51, 1959 INVENTOR. M4meu5 ct Zoe/1w BY nap A t WATTOAAQA M. c. LOGAN 3,047,945

DEVICE FOR TENSIONING BUNDLING STRAPS 2 Sheets-Sheet 2 Aug. 7, 1962 Filed Aug. 31, 1959 I Q A E INVENTOR. 50 MHZ/05 C. LOG/4N Z wwwgx United States Patent 3 047 945 DEVICE FOR TENSIGNHQG BUNDLlNG STRAPS Maurus C. Logan, Elizabeth, NJL, assignor to The Thomas & Betts (10., Elizabeth, N.J., a corporation of New Jersey Filed Aug. 31, 1959, Ser. No. 837,082 Claims. ((11. 30-134) movement, the tool being subsequently actuated to closed position to perform a severing operation on the extended free end portion of the strap.

More specifically, the invention resides in a hand tool of the parallel action pliers type which is particularly adapted for tensioning, locking and severing individual flexible plastic bundling straps of the character disclosed in my co-pending application Serial No. 744,267, filed June 24, 1958, whereby the application of such straps on a plurality of bunched insulated electric conductors, for example, may be effected at spaced points therealong with facility and dispatch and with all of the tied straps under equal tension. 7

Heretofore, plasti'c'tie or bundling straps, as disclosed in my aforesaid co-pending application, were looped about bunched parallel electric conductors, and successively drawn taut and twisted either by hand or with the aid of a conventional pair of pliers having side cutting edges, and the extended free end portion of the strap severed from its looped portion in known manner. The aforesaid method of applying flexible plastic tie straps on and about insulated wire conductors, disposed in bunched parallelism, was unsatisfactory because of the time required and the non-uniformity of tension obtained among a large number of such straps spaced along the bunched conductors.

Accordingly, it is an object of the invention to provide a novel hand tool of the character described which is particularly adapted for successively placing looped bands under uniform tension.

Another object of the invention is to provide a hand tool of the character described whereby plastic bundling straps may be uniformly tensioned on and about a plurality of articles, disposed in bunched parallelism, and each strap separately held under tension while the tool is rotated 90 degrees from its normal operating position to lock the strap upon itself before fully closing the tool to perform a severing operation thereon to discard the surplus free end portion thereof.

With the above and other objects in view, the invention resides in the novel construction, combination, and arrangement of parts, the novel features of which are set forth with particularity in the appended claims, the invention itself, however, both as to its organization and method of operation, together with additional objects and advantages thereof, being best understood from the following description of a specific embodiment thereof, when taken in connection with the accompanying drawing in which:

FIG. 1 is a perspective view of the subject hand tool as constructed in accordance with the invention;

"ice

FIG. 2 is a fragmentary side view in elevation showing the hand tool in open position and as initially applied to the free end portion of a looped bundling strap preparatory to tensioning the same about a plurality of articles disposed in bunched parallelism;

FIG. 3 is a view similar to FIG. 2, partly in perspective and showing the tool in partly closed position with the looped strap under tension and the tool about to be rotated substantially 90 degrees to twist aportion of the strap into alignment with a locking means adjacent the opposite end portion thereof;

FIG. 4 isv a view in perspective of a pair of nose plates in the position in which they are secured to the jaws of a hand tool in accordance with the invention;

FIG. 5 is a fragmentary view in elevation of a bundle of elements as tied with a flexible plastic strap under tension and as locked upon itself against relative reverse movement in accordance with the invention;

FIG. 6 is an elevational view of the flexible plastic strap as disclosed in my co-pending application;

FIG. 7 is a transverse sectional View taken on the line 7 1 of FIG. 6.

FIG. 8 is a modified form of the pliers type hand tool shown in FIG. 1, in which one side of its jaws is unobstructed for the lateral insertion therebetweerr of a linear article to be manipulated;

FIG. 9 is a modification of the handle portion of the open sided hand tool shown in FIG. 8;

FIG. 10 is a fragmentary sectional view taken on the line 9-9 of FIG. 9; and

FIG. 11 is a fragmentary sectional view taken on the line 10-10 of FIG. 9.

Referring to the drawings and to FIGS. 1 and 4 in particular, the invention resides in a pliers type hand tool, generally indicated at 10, comprising a pair of crossed members 12 pivotally connected as at 14, and solid jaws 16, of rectangular cross-section, pivotally mounted on one end of said members 12, and adapted to have parallel motion when moved to and from closed position upon pivotal movement of said members 12. Each of the members 12 comprises a sheet metal stamping formed to provide a closed, hollow handle portion 18, and a pair of fiat, integral end plates 20 disposed in spaced parallelism for mounting one of the jaws 16 therebetween, each of said jaws being provided with an open ended slot 22 in one end thereof for the reception of a guide pin 24 disposed transversely of said end plates 20, whereby to maintain the jaws in parallelism during angular manipulation of the pivoted members 12 toward and away from each' other. The respective jaws 16, and pivoted members 12, are yieldably maintained in open position by means of a pair of retractile springs 26, each having one end thereof suitably anchored within one hollow handle portion 18, and its exposed opposite end suitably connected to the slotted end of its correlated jaw 16, whereby the pivoted members 12, including the jaws 16, are biased into and maintained in open position, the hollow handle portions the outer face of each jaw by means of suitable screws 34,

as clearly shown in FIGS. '1, 2 and 3. The other leg of the angle plates 30 and 32 extending in opposite directions across the nose end of the jaws 16 at right angles to the opposing faces 36 of the jaws and in overlapping sliding contact relation as best shown in FIG. 4.

Further in accordance with the invention, the leg 38, of the angle plate 3%), is provided with an open ended, transverse slot 40, extending inwardly of one marginal edge thereof with its defining edges at the open end thereof rounded, as at 42, for the free insertion therethrough or laterally thereinto of the extended free end portion of a plastic strip S, in a path normal to the axis of turn of said tool, which has been looped upon itself as shown, for example, in FIG. 3, the width of the slot 4% being substantially equal to the thickness of the body portion of the strap S, and the length of said slot, relatively greater than the width of the strap S, to be received therein.

Further in accordance with the invention, the leg 44, of the angle plate 32, is provided with an L-shaped cutout to provide a narrow upstanding arm 46, adapted to pass across the open end of the slot 40, upon partial closing of the jaws 16, to close the open side thereof whereby to reduce its length to a dimension slightly less than the width of the body of the strap S, when positioned therein whereby the strap is frictionally held against relative reverse movement, the angle plate 30, being provided with a notch 48 to clear the free end of the upstanding arm 46, in its extended position. The remaining margin of the cut-out in the leg 44 of the angle plate 32, is formed to provide a cutting edge 50, movable upwardly across the slot 40 in shearing relation in response to movement of the jaws 16 to closed position, whereby to sever the strap S, when extended through the slot 40, as exemplified in FIG. 2.

Further in accordance with the invention, means for drawing a strap S taut about a plurality of bunched parallel elements E, in small successive increments of adjustment comprises an arcuate pawl 52 provided with a pair of spaced, parallel ears 54 depending from one end thereof which are suitably apertured to serve as hinge members, the pawl being pivotally mountedacross the inner face of the lower jaw 16, adjacent its nose end, by means of a transverse hinge pin 56, extending through the ears 54 and lower one of the jaws 16, as seen in FIG. 1, whereby the pawl 52 is adapted to have limited angular movement between the opposing faces 36 of the jaws toward the fulcrum 14, of the tool 10, from a normal upright position to a substantially horizontal position.

As best shown in FIGS. 2 and 3, the pawl 52, is yieldably maintained in normal upright position by means of a spring influenced headed pin 58, disposed in a suitable aperture extending through the lower one of the jaws 16, at an angle thereto, a short coil spring 60, carried by the pin 58, between its head end and an angular notch formed in the inner face of said jaw 16, acting against the concave side of the pawl 52, in known manner.

As shown in FIGS. 1 and 2, the convex side of the free end portion of the pawl 52, is suitably abraded, knurled or provided with a plurality of serrations 62, or the like whereby the pawl 52, is adapted to bite into the linearly ribbed underside of a strap S, as seen in FIG. 2, and draw the tail-end portion thereof, extending rearwardly through the tool 10, relative to its looped portion, in response to repeated partial closing of the handle members 18, until the strap S has been drawn taut on a bundle of elements E, whereupon the tool is rotated through an angle of 90 degrees, with the jaws 16, remaining in the position exemplified in FIG. 3, to lock-twist the extended end portion of the strap S, relative to a portion of its head end, as seen in FIG. 5, at which time the tool is finally brought to closed position and the strap severed by the shearing action of the cutting edge 50 of the angle plate 32, across the slot 40, in the angle plate 30.

In a modified form of the invention, as shown in FIG. 8, the open end of each of the handle members 18, terminates in a single, fiat plate 20', to one side of the longitudinal center thereof, to which the respective jaws 16,

A are pivotally secured asby means of a suitable screw-bolt rivet or the like, whereby the opposite side of each jaw 16, remains unobstructed for placement of the tail-end portion of a looped strap S, into the slot 40 sidewise or laterally of the open side of the tool 16, as seen in FIG. 8.

In a further modified form of the invention, as shown in FIG. 9, the open end of each of the handle members 18, terminates in a single flat plate 20", to one side of the longitudinal center line thereof as in FIG. 8, with the exception that the said flat plate is longer in order that it may be bent upon itself as at 64 in FIG. 10, to provide an inverted, U-shape end portion for pivotally securing one of the jaws 16, therein by means of a screw bolt 66 or the like.

In FIG. 11, there is shown a modified form of spring mounting arrangement for biasing the pawl 52' as in FIG. 9, wherein the concave face of the pawl is suitably recessed inside of its side margins, as at 68, to receive the intermediate bent leg 7fl, of a coiled torsion spring 60', the lower one of the jaws 16 being also provided with a suitable recess between its side margins, as at '72, to provide clearance for the torsion spring and hinge pin 56, connecting the pawl 52' thereto, and an abutment for the respective parallel legs at the opposite ends of the spring.

While the invention has been illustrated and described with respect to preferred embodiments thereof, it is to be expressly understood that various changes and modification may be made therein without departing from the inventive concept underlying the same. Therefore, the invention is not to be limited except as is necessitated by the prior art and the scope of the appended claims.

What is claimed is:

1. A hand tool for tensioning and subsequently cutting a plastic strap when looped about a plurality of bunched articles, comprising a pair of jaw members connected for movement toward and away from each other, a first and second complementary angle plate each having one leg thereof secured to said jaw members with the remaining leg thereof extending therefrom in opposite directions at right angles to the opposing faces of said jaw members across the nose end thereof in overlapping sliding engagement with each other upon movement of said jaw members toward and away from each other, the extended leg of said first angle plate being provided with a transverse, open ended slot along one side edge thereof adapted to freely receive said strap therethrough, the extended leg of said second angle plate being partly reduced in width to provide a narrow upstanding arm adapted to overlap the open end portion of said slot not occupied by said strap upon movement of said jaw members toward each other to reduce the length of said slot to substantially the width of said strap to hold said strap in said slot against relative movement.

2. A hand tool as set forth in claim 1, characterized further in that said first angle plate is provided with a short rectangular open ended slot extending transversely from said one side edge thereof at its point of bend, and said extending leg thereof spaced from the nose end of its correlated jaw member to provide a clearance passage for the free end portion of said upstanding arm upon movement of said jaw members toward closed position.

3. A hand tool as set forth in claim 1, characterized further in that the normal width portion of the extended leg of said second angle plate, at the base of said upstanding arm, is provided with a transverse cutting edge parallel with the strap receiving slot in said first angle plate whereby said strap is severed upon movement of said cutting edge across said slot in response to movement of said jaw members toward closed position.

4. A hand tool as set forth in claim 1, wherein the first angle plate is provided with a notch in one edge thereof aligned with the corresponding edge of its extended leg at the juncture of the bend therebetween, the free end portion of said upstanding arm passing into said notch in said angle plate when said jaw members are moved toward each other, the extended leg of said second angle plate being L-shaped to form said upstanding arm and a cutting edge normal thereto, said cutting edge being aligned with said strap in said receiving slot in said first angle plate whereby when said jaw members are moved toward each other said cutting edge will sever said plastic strap.

5. A hand tool as set forth in claim 1, wherein said jaw members comprise elongated, rectangular members including a pair of pivotally connected handle members having off-set, flat, nose-end portions disposed in a common plane and pivotally connected at their free ends to 1,085,804 Dunn Feb. 3, 1914 1,206,985 Bush Dec. 5, 1916 1,623,044 Butcher et a1 Apr. 5, 1927 2,320,460 Muller June 1, 1943 2,622,460 Keeble Dec. 23, 1952 2,882,934 Gerrard Apr. \21, 1959 

